Phosphorus chemistry such as zinc dialkyldithiophosphate (ZDDP), and amine phosphates, are known anti-wear agents in many lubricants. It is believed that phosphorus chemistry (e.g. ZDDP antiwear additives) protects metal surface of mechanical devices by forming a protective film on metal surfaces. However, many phosphorus antiwear agents have been identified as having some detrimental impact on either the mechanical devices being lubricated, or on the environment.
For example, engine lubricants containing phosphorus and sulphur compounds such as ZDDP have been shown to contribute in part to particulate emissions and emissions of other pollutants. In addition, sulphur and phosphorus tend to poison the catalysts used in catalytic converters, resulting in a reduction in performance of said catalysts.
There has been a commercial trend for reduction in emissions (typically reduction of NOx formation, SOx formation) and a reduction in sulphated ash in engine oil lubricants.
In engine lubrication ashless phosphorus chemistry such as amine phosphates is believed to in part result in increased corrosion, typically lead and/or copper corrosion. Copper and lead corrosion may be from bearings and other metal components derived from alloys using copper or lead. Amine salts are also known to contribute to the degradation of fluorocarbon seals.